Grease a rimmed baking sheet and line it with parchment paper. Then grease the parchment paper as well. Dust this all with a fine layer of flour.

To a small bowl add your baking powder, baking soda, salt and spices and mix them together with a fork.

​Next, to the bowl of a stand mixer add your eggs, white sugar and brown sugar. With the paddle attachment, beat until the eggs start to look thick. This will take about three minutes. Next, you will add your pumpkin purée. Mix this until everything is fully combined without streaks.

Now add in your starter and the spice mixture, and beat on medium low speed for about 30 seconds. Scrape the bottom of the bowl and mix for 10 more seconds. You don't want to overmix here. However, you want to make sure that the starter is completely incorporated. Use a spatula to transfer the mixture to the prepared pan. Smooth the batter out and push it into the corners of the pan.

While the cake is in the oven, find a kitchen towel that is at least as big at the baking sheet. Try to find a towel with a low nap (less fuzzy). Spread it out on the counter. Dust the towel with a fine layer of powdered sugar. A sifter works great here!

Bake the cake for 12-15 minutes. To test it, take the tip of a knife and insert it in the center of the cake. If the tip comes out clean the cake is done. If batter clings to the knife, it needs a few more minutes. The surface of the cake should be golden brown and a beautiful orange color!

After you take the cake out of the oven, you are immediately going to flip the cake out of the pan and onto the prepared towel. This part takes some bravery, but as long as you prepared your pan you shouldn't have any trouble! First I like to run a butter knife along the edges of the pan. This ensures that none of the edges stick. Then just invert the pan over the towel and the pumpkin cake should pop right out!

As soon as the cake is flipped onto the towel, begin with one of the shorter edges and use the towel to roll the cake up into a log. Set the log, towel and all, onto a wire rack to cool completely.

While you're waiting on your cake to cool, go ahead and make your filling. For best results, use softened cream cheese and softened butter that have been sitting at room temperature for about thirty minutes. This ensures that your filling comes together nicely without lumps. Any time you're making a buttercream of sorts, you want to beat your ingredients together for a full five minutes. This is the best way to make sure you end up with fluffy and delicious frostings and fillings! For the cream cheese filling, Add all of your ingredients to the bowl of a stand mixer. Beat with the paddle attachment at medium speed for five minutes, or until light and fluffy. Scrape the sides of the bowl once or twice along the way.